Gaya APA
Rubin, Gretchen. (2009).
The happiness project .
New York:
HarperCollins Publisher.
Gaya Chicago
Rubin, Gretchen.
The happiness project.
New York:
HarperCollins Publisher,
2009.
Text.
Gaya MLA
Rubin, Gretchen.
The happiness project.
New York:
HarperCollins Publisher,
2009.
Text.
Gaya Turabian
Rubin, Gretchen.
The happiness project.
New York:
HarperCollins Publisher,
2009.
Print.